Water-tube steam boiler



June 3, 1930.

J. HANRAHAN WATER TUB E STEAM BOILER Filed Nov. 1, 192

Patented June 3, 1930 I E P T NT W A'l ER -T UBESTEAIVI OI ER Application filed November My invention relates to 'water tubesteam boilers and is an improvement over the invention of my Patent 1,552,296fdated S'eptember 1, 1925, fora steam boiler. The boiler V ofmy present inventi'on is of substantially the same shape as that of my patent but I eliminate the intermediate combustion wall and the central water drum. 1 also eliminate the wa ter legs and introduce .a line of large sturdy tubes connected from the lateral steam and water drums to the mud drum at the base, these forming in a sense ribs and being termed rib tubes, such tubesare partly :em-

bedded in the refractory composition of the furnace walls.

An object of my invention is the construe tion of an internally fired and water tube boiler in whichthe furnace is enclosed by the 7 tubes, suchtubes leadingto difierent'drums' 0 and to a steam drumfat the top.

Another object of my invention is haying refractory walls from which'the heat rays are reflected across the path of the escaping gases and aid in bringing such gases to a high tem perature, giving'a moreperfect combustion, Another obj ect of my invention is to prevent the breaking down of the refractory fun miss walls through excessive temperature,

this being done by'utilizing the rib tubes 0 which have circulating water therein, these tubes protecting and cooling the furnace wall as well as rapidlyheating-the water for gencrating steam.

Another object of my invention is the sup- 1 porting of a plurality of steamand water drums and a steam Vdr'umatthe top without the use of intermediary supports, hangers,

rollers, or the like. The various tubes connecting the mud drum, the lateralsteam and, water'drums, and the steam drum, givethe supportnecessary and thus allow for equalizing expansion of the metal parts of the boiler..

stood from the followlng description and drawings, in which: V

Figure 1 is a transverse vertical section.

through the boilerf' ,7 I isja longitudinal section taken on nect the side walls with the steamand water My invention-willbe more readily the floor 2 of the furnace and the series of Y r water tubes 3 extend upwardly at an angle forming a substantially V-shaped' nest of tubes, these tubes being connected at their upg per ends with a p'airof steam and water." drums 4, forthe generationofsteam from; the water. -Another' set of tubes5lead up; wvardly from the steam andwater drums and. connect to the steam'drum 6. A series of; relatively large rib tubes 7'are connected ,to the steam and water drums, asde signated by the numeral 8, on their lower outward ,side and lead downwardly,'being connected tothe mud'drum adjacent the bottom as indicated by the numeral 9. L The grates 10 of the furnaceaie on opposite sidesfof the mud drum 9 and preferably-adj acent the top of said drum running lengthwise of'the furnace; Perforated bafiie walls 11 form a V-shaped structure lengthwise of the'mud: druml and the steam and water drums 4,.tl1e'se walls prefer- I r I have their ends'connect-ed to the drums at substantially the line of the water'level, and

atop perforatedlarchlii extends between the drums 4, being supportedon the'tubes '12. I r, The furnacestructure is'builtiupbyhav ing sidewalls 14: and a roo f section 14. The. rib tubes are preferably encased to half di-' ameter in a fire resisting composition below vthegrates and thence continuing above the' side of'the' grates. Insulating walls 17:'con'- drums 4;. v v

A steam pipe 18 is connected to the top of' "In order to new the sediment at the the steamdrum and pipes 19 connect'with the mud drum I employ an inlet and blow-off pipes 21 and 22, connected to the opposite ends of the drums adjacent the base, by this means utilizing feed-pump water pressure the mud may be cleared out of the drum or any sludge that accumulates there. One of these pipes will also be utilized with the feed water. H

The operation of the improved boiler is substantially as follows. Fuel 23 is burned on the grates 10, or gas, oil or pulverized fuel is projected above the grates into the chambers defined by the banks of tubes 3 and the walls 14. These chambers may be called initial combustion chambers as most of the combustion takes place therein. The unburnt fuel, air and products of combustion then pass between the tubes 3 and through the perforations in the perforated walls 11, entering the chamber 25 which is between the banks of tubes. This chamber may be called a secondary combustion chamber. It will be noted thatvin this chamber, two streams of partly burnt fuel, air and products of combustion meet,,and the effect of their meeting is to produce a, whirling. The effect of the whirling is to bring the unburnt fuel into contact with the available oxygen, thus reviving combustion in this chamber and completing the combustion. The products of combustion then pass upwardly out of the top of this chamher, passing between the drums 4 and the equalizing tubes 12, through the perforations in the perforated arch l3 and finally striking against the steam drum or super-heating drum 6. The products of combustion are confined about the steam or super-heating drum 6 by an outer casing '27, and pass through a longitudinal passage 28 extending rearwardly of the steam drum to be discharged through a stack 29. The water, on

being heated within the tubes 3, rises therein, flowing into the drums 4, and in a similar manner water rises from the mud drum 9 through the rib tubes 7 up to the drums 4. The steam generated within the drums4 is carried=therefrom through the pipe 5 to the steam drum 6 where it may be dried out and super-heated, being out of the presence of its liquor, and discharged into the steam pipe.

From the above described construction and description of the operation, it will be appreciated thatthe improved boiler provides three substantially equal sized combustion chambers, two of which act as initial combustion chambers within which most of the fuel is burned, and the third chamber constituting a secondary combustion chamber is so arranged that the gases from the initial combustion chambers will flow into it and meet to revive and complete the combustion. The combustion of fuel being practically complete in the boiler, the efficiency of the boiler is quite high. Furthermore, as it is possible for flame indicated at 24 to circulate about the tubes 3 befaces on the rib tubes 7 which are heated,

and also exposed surfaces on the drums 4t and 9 which serve to transmit heat to the water for the generation of steam. The embedded portions of the rib tubes 7 also receive a great amount of heat from the refractory walls 14 and in a similar manner the drums where they contact with the refractory walls will receive a great deal of heat from these walls.

Various changes may be made in the principles of my invention without departing from the spirit thereof, as set forth in the description, drawings and claims.

I claim: I

l. A water tube steam boiler comprising a mud drum, two banks of tubes connected to the mud drum and divergently extending upward therefrom, two steam and water drums arranged above the mud drum, one steam and water drum being connected to one bank of tubes and the other steam and water drum being connected to the other bank, means providing walls connecting each steam and water drum to the mud drum, said banks of tubes serving to divide the space between the drums and walls into three chambers, the chambers between the banks of tubes and the adjacent walls constituting initial combustion chambers and the chambers between the banks of tubes constituting a secondary combustion chamber, there being passages between the tubes of each bank permitting fuel and the products of combustion to pass therethrough from the initial combustion chambers into the secondary combustion chamber and to meet therein in opposition and revive or complete the combustion before passing upwardly between the steam and water arranged above the secondary combustion chamber in the path of the products of com bustion issuing therefrom and connected to the steam and water drums.

2. A water tube steam boiler comprising a mud drum, two banks of tubes connected to the mud drum and divergently extending upward therefrom, two steam and water drums arranged above the mud drum, one steam and water drum being connected to one bank of tubes and the other steam and water drum being connected to the other bank, means providing walls connecting each steam and water drum to the mud drum, said banks of tubes serving to divide the space between the drums and walls into three chambers, the chambers. between the banks of tubes and the adjacent walls constituting initial combustionchambers and the chambers between the banks of tubes constituting a secondary combustion chamber, there being passages between the tubes of each bank permitting fuel and the products of combustion to pass therethrough from the "initial combustion i chambers into the secondary combustion chamber and to 'meet' therein in'opposition and revive or complete-the combustion before passing upwardly between the steam and water drums, and rib tubes connecting the steam and water drums to the mud drum, said ribtubes being exposed to the interior of the initial "combustion chambers.

3. A water tube'steam boiler comprising a mud drum, two banks'of tubes connectedto the mud drum and divergently extending upward therefrom, two steam and water the drums and walls into threechambers, the

chambers betweenthe banks of tubes and the adjacent walls constituting initial combustion chambersan'd the chambers between thebanks of tubes constituting a secondary combustion cham ber, therebeing passages between the tubes of each bank permitting fuel and the productsof combustion to. pass there'- through fromthe initial combustion chambers into the secondary combustion chamber and to meet therein in opposition and revive or complete the combustion before. passing upwardly between [the steam I and water drums, and equalizing tubes connecting the steam and water drums across the top of the secondary combustion chamber between which the products "of combustion from the secondary combustion chamber may pass.

4=. A water tube steam boiler comprising a mud drum' two banks of'tube's connected to the mud drum and divergently extending up Ward therefrom, two steam andwater drums arranged above the mud drum, one. steam and water drum being ,connectedto one bank of tubes and the other steam and water drum being connected to the'other bank, means providing walls connecting each steam and water drum to the mud drum, said banks eof tubes serving to divide the space between the drums and wallsinto three chambers, the chambers between the banks of tubes and the adjacent walls constituting initial combustioncham-j bers and the chambers between the banks of] tubes constituting a secondary combustion chamber, there being passages I between the tubes of each bank permitting fuel and the products of combustion to pass therethrough 7 from the initial combustion chambers'into the secondary combustion chamber and to meet therein in opposition i and revive or complete the combustion before passing upwardly between the steam and water drums, and equalizing tubes connecting the steam and water drums across the top of the secondary combustionchamber between the steam drum. V ,i I 6. A water tube steamboiler comprising a which the products of'combustion'from the secondary combustion chamber may pass, and

a steam super-heatingdrum arranged above sald equalizingtubes and connected to the steam and water drums against which theproducts of combustion may strike after passing between the equalizing tubes. V .5. A water tube steam boiler compri a mud drum,twobanks of tubes connected to the'mud drum and divergentlyextending sing A upward therefrom, twosteam and' water 7 drums arranged" abovethe 'mud' drum, onesteam and waterdrum-being connected to'one i bank of tubes and the othersteam and water drum being connected to the other bank,

means providing walls connecting each steam and water drum to the muddrum,saidbanks of tubes serving to divide the space between I the drums and walls into three chambers, the

chambers between the banks of 'tube'sand the adjacent walls'constituting initial combustion chambers and the chambers beween the banks of tubes constituting a secondary combustion chamber, there being passages between-the tubes of each bank permittingrfuel and'the products of combustion to' pass therethrough fromthe' initial combustion chambers into the secondary combustion chamber and to meet therein in oppositionand revive or COH1- vplete the combustion beforepassing upward" lybe'tweenthe steam and water drums," and equalizing tubes connecting the steam and water drums across the top of the secondary combustion chamber between which the prodnote; of combustion from the secondary combustion chamber may pass, a'nd'a steam superheating drum arranged above said equalizing tubes and connected to the steam and water drums against which the products of combLlSlJlOl'l may strike after" passing between the 'equallzing tubes, and means providlng a perforate'd wall connecting the'steam andwater drums over the equalizing tubes and below mud drum, two'banks of tubes connected to the mud drum and divergently extending upwardatherefrom, two steam and ,-water drums arranged above the'mud drum, one

steam and water drum being connected to one bank of tubes and the: other steam and water drum being connected to the other 1 bank, means provldlng walls connectingieach V steam and waterdrumto the mud drum, rib

tubes connecting each steam andwater drum to the mud'drum, said banks of tubes serving to divide the space between the drumsand I walls into three chambers, thechambers .be-

tweenrthe banks of tubes and the adjacent walls constituting initial combustion cha ms bers and the chamber'between the .b'anksof tubes constituting a sec ondary combustionv chamber, there being passages between the tubes of each bankpermitting gases topass therethrough from the initial combustion vive or complete the combustion before passing upwardly between the steam and water drums.

' 7. A water tube steam boiler comprising a mud drum, two banks of tubes connected to the mud drum and divergently extending upward therefrom, two steam and water driuns arranged above the mud drum, one steamand water drum being connected to one bank of tubes and the other steam and water drum being connected to the other bank, means providing Walls connecting each steam and water drum to the mud drum, rib

7 tubes connecting each steam and water drum bers and the chamber between the banks of tubes constituting a secondary combustion chamber, there being passages between the tubes of each bank permitting gases to pass therethrough from the initial combustion chamber into the secondary combustion chamber and to meet therein in opposition and revive or complete the combustion before passing upwardly between the steam and waterdrums, the opposed sides of the banks of tubes being covered by a perforated wall.

8. A water tube steam boiler comprising a mud drum, two banks of tubes connected to the mud drum and divergently extending upward therefrom, two steam and water drums arranged above the mud drum, one steam and water drum being connected to one bank of tubes and the other steam and water drum being connected to the other bank, means providing walls connecting each steam and.

water drum to the mud drum, rib tubes connectlng each steam and water drum to the mud drum, said banks of tubes serving to divide the space between the drums and therethrough from the initial combustion chamber into the secondary combustion chamber and to meet therein in opposition and revive or complete the combustion before passing upwardly between thesteam and water drums, and a steam super-heating drum arranged above the secondary combustion chamber in the path of the products of combustion issuing therefrom and connected to the steam and water drums.

9. A water tube steam boiler comprising a mud drum, two banks of tubes connected to the mud drum and divergently extending chamberinto the secondary combustion chamupward therefrom, two steam and water her and to meet therein in opposition and redrums arranged above the mud drum, one steam and water drum being connected to one bank of tubes and the other steam and water drum being connected to the other bank, means providing walls connecting each steam and water drum to the mud drum, rib tubes connecting each steam and water drum to the mud drum, said banks of tubes serving to divide the space between the drums, and walls into three chambers, the chambers between the banks of tubes and the adjacent walls constituting initial combustion chambers and the chamber between the banks of tubes constituting a secondary combustion chamber, there being passages between the tubes of each bank permitting gases to pass therethrough from the initial combustion chamber into the secondary combustion chamber and to meet therein in opposition and revive or complete the combustion before passing upwardly between the steam and water drums, equalizing tubes connectthe steam and water drums across the top of the secondary combustion chamber between which the products of combustion from the secondary combustion chamber may pass.

10. A water tube steam boiler comprising a mud drum, two banks of tubes connected to the mud drum and divergently extending upward therefrom, two steam and water drums arranged above the mud drum, one 7 steam and water drum being connected to one bank of tubes and the other steam and water drum being connected to the other bank, means providing walls connecting each steam and water drum to the mud drum, rib tubes connecting each steam and water drum to the mud drum, said banks of tubes serving to divide the space between the drums and walls into three chambers, the chambers between the banks of tubes and the adjacent walls constituting initial combustion chambers and the chamber between the banks of tubes constituting a secondary combustion chamber, there being passages between the tubes of each bank permitting gases to pass therethrough from the initial combustion chamber into the secondary combustion chamber and to meet therein in oppositionand revive or complete the combustion before passing upwardly between the steam and water drums, equalizing tubes connecting the steam and water drums across the top of the secondary combustion chamber between which the products of combustion from the secondary combustion chamber may pass, and a steam super-heating drum arranged above said equalizing tubes and connected to the steam and water drums against which the products of combustion may strike after passing between the equalizing tubes.

In testimony whereof I have signed my name to this specification.

JOHN C. HANRAHAN. 

